ASP.NET中后台注册js脚本使用的方法对比
用Page.ClientScript.RegisterClientScriptBlock 和Page.ClientScript.RegisterStartupScript:区别:
1.使用Page.ClientScript.RegisterClientScriptBlock
c#代码
代码如下:
<%@ Page Language=”C#” %>
<script runat=”server”>
protected void Page_Load(object sender, EventArgs e)
{
string myScript = @”function AlertHello() { alert(‘Hello ASP.NET'); }”;
Page.ClientScript.RegisterClientScriptBlock(this.GetType(),
“MyScript”, myScript, true);
}
</script>
<html xmlns=”http://www.w3.org/1999/xhtml” >
<head><title>
Adding JavaScript
</title></head>
<body>
<form method=”post” action=”JavaScriptPage.aspx” id=”form1”>
<div>
<input type=”hidden” name=”__VIEWSTATE”
value=”/wEPDwUKMTY3NzE5MjIyMGRkiyYSRMg+bcXi9DiawYlbxndiTDo=” />
</div>
<script type=”text/javascript”>
<!--
function AlertHello() { alert(‘Hello ASP.NET'); }// -->
</script>
<div>
<input type=”submit” name=”Button1” value=”Button” onclick=”AlertHello();”
id=”Button1” />
</div>
</form>
</body>
</html>
2.使用Page.ClientScript.RegisterStartupScript
RegisterStartupScript 方法与RegisterClientScriptBlock方法最大的不同是:RegisterStartupScript 把script放置在 ASP.NET page的底部,而RegisterClientScriptBlock把script放置在ASP.NET page的顶部。
如果你的页面中有如下代码:
代码如下:
<asp:TextBox ID=”TextBox1” Runat=”server”>Hello ASP.NET</asp:TextBox>
protected void Page_Load(object sender, EventArgs e)
{
string myScript = @”alert(document.forms[0][‘TextBox1'].value);”;
Page.ClientScript.RegisterClientScriptBlock(this.GetType(), “MyScript”, myScript, true);
}
此页面运行时会报错,原因是JavaScript function先于text box被安放于浏览器。因此JavaScript function找不到TextBox1。
c#
代码如下:
protected void Page_Load(object sender, EventArgs e)
{
string myScript = @”alert(document.forms[0][‘TextBox1'].value);”;
Page.ClientScript.RegisterStartupScript(this.GetType(), “MyScript”, myScript, true);
}
这段代码把JavaScript function放置于ASP.NET page底部,因此JavaScript运行时它能找到TextBox1。
3.使用Page.ClientScript.RegisterClientScriptInclude
许多开发者把JavaScript放置在.js文件中,使用RegisterClientScriptInclude方法可以注册.js文件中的JavaScript。
c#
代码如下:
string myScript = “myJavaScriptCode.js”
Page.ClientScript.RegisterClientScriptInclude(“myKey”, myScript);
<script src=”myJavaScriptCode.js” type=”text/javascript”></script>